Reimplement RegExp in JavaScript

Reimplement RegExp in JavaScript

Regular expressions are used in many places to filter and validate input. While they are cute and powerful, they are usually hard to write and debug. So why not implement the entire RegExp object in JavaScript, such that each execution step can be visualized and debugging becomes easy? And what happens if you build a RegExp JIT in JavaScript that gets JITed by the JavaScript JIT … ;)